RMS Meter Saves Investor Big Bucks

I was once approached by a gentleman who was about to invest in a "black box" that was purported to produce more power out than what was put in. He had taken the device to a local university for evaluation, knowing it would be rare to find a device that actually pulled off this magic.

What he showed me was a box with metering on the input and output, an AC plug, and an incandescent light bulb for a load. The kids (hopefully freshmen and not graduates) had measured currents and voltages and found their measurements substantiated the claims, but no one would put their name on a document stating this.

Having taught instrumentation and calibration for 10 years, I knew most all of the pitfalls one could run into while measuring power. First thing I did was drag out and dust off an old oscilloscope and look at the waveforms. The input, of course, was a good, clean sine wave, but the output was a ragged, distorted 60Hz mess.

I asked the potential investor to find out what meters were used to make the measurements. He made a call and gave me the brand and model. It was a typical shop-grade VOM that I was very familiar with. The meter's AC circuit is a peak detector diode circuit and the scale is calibrated to read RMS (.707xpeak).

I then grabbed a handy, true RMS meter and duplicated the measurements made previously at the university. Wow, what a difference! Instead of 20 percent more power out than in, it was almost the opposite. My test convinced the investor, so no money changed hands. I'm sure he is happy today that he didn't fall into the trap.

This entry was submitted by John Gray and edited by Rob Spiegel.

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If it breaks the laws of physics, it probably is not true. This situation is very reminiscent of the cold fusion controversy.

The laws of physics can be ammended, but then the correspondence principle kicks in. You may find a new physics, but it has to agree with the current physics where that physics works well. Quantum mechanics and classical mechanics are the cononical example.

Sam finally has Bugs tied and standing on the edge of the platform, with Sam sawing away at the board, gloating: "Now ya smarty-pants, let's see ya get out-in this one! This time, you're a-diving!" However, as soon as Sam cuts through the board, it's the ladder and platform that falls, leaving the cut plank suspended in mid-air. Bugs turns to the camera and cracks: "I know this defies the law of gravity, but, you see, I never studied law!"

Some 30 years ago, my mother actually invested in a similar "techno-scam". Some whiz-kid had allegedly invented a substitute for an external antenna for car radios. I asked her to get a copy of the technical description. What was described was, in actuality, a 3-electrode neon bulb (imagine an NE-2 with a third electrode). These were commercially-available components that could be described as a "soft, gaseous triac". Anyway, this device was to be placed inside the metal enclosure of the radio and serve as the antenna (claimed to work for AM and FM). Of course, this violates all that's known about antenna and electromagnetic waves. I told her she'd better get her money back before others discovered they were being bamboozled by this guy. Fortunately, she did ... and predictably, the others never saw their money again.

The most recent device to be advertised the last couple years with more energy put out than put in is the so called "Amish Mantle". When one buys this wooden cover for several hundred dollars, he gets free a plug-in space heater "that actually puts out more heat than goes into it." How this occurs is not actually explained; but how many consumers have the knowledge and resources to verify this? Electric space heaters must be fairly popular because so many are sold. Their value is in keeping small space warm and cozy instead of heating the rest of the house to the same temperature. Since electric resistance heat is usually the most expensive heat to consume, its relative worth would have to be calculated against the cost of the whole house heating system.

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